Line Spectra Line spectrum of Hydrogen is produced when an electron drops from a higher-energy orbit to a lower energy orbit. Specifically, E photon = E 2 - E 1 = h Specifically, E photon = E 2 - E 1 = h
Bohr Checked it with Math. l Used mass and charge of the electron together with Planck’s constant and calculated where the spectral lines should be and they were! l Problem -- only worked for Hydrogen!
Bohr model of the atom l The Bohr model is a ‘planetary’ type model. l Each principal quantum represents a new ‘orbit’ or layer. l The nucleus is at the center of the model.
Hydrogen Spectrum (cont.) Each line of the Hydrogen spectrum is produced by and corresponds to the emission of photons with specific energies (E = h )
Bohr Model Holt Online Learning Holt Online Learning
Heisenberg uncertainty principle l In order to observe an electron, one would need to hit it with photons having a very short wavelength. l Short wavelength photons would have a high frequency and a great deal of energy.
Heisenberg uncertainty principle l If one were to hit an electron, it would cause the motion and the speed of the electron to change. l Lower energy photons would have a smaller effect but would not give precise information.
Bohr vs. Schrödinger Orbits vs. Orbitals Bohr -- definite distinct orbits populated by electron particles.
Bohr vs. Schrödinger Orbits vs. Orbitals Schrödinger -- electron are waves (de Broglie) with a certain probability (mathematical model) of being found in three dimensional regions around the nucleus - orbitals
Comparing Models of the Atom – A review Holt Online Learning Holt Online Learning